Several attempts have been made to provide an effective monitoring system of this kind which will comply with the stringent requirements of public water authorities regarding cross connection and the minimum height of fresh water inlet valves above spill levels of swimming pools. A breaker tank is generally required which of necessity is of such large proportions as to be difficult to site on domestic premises.
Of course, ball float valves, and similar water level maintaining devices used in other applications such as water cisterns, are well-known but would not be either of sufficiently compact form or readily convertible for compliance with water authority regulations, for use in the instant application. Furthermore, such existing devices do not provide a ready and convenient facility for water level adjustment which should be available to the owner of a domestic swimming pool.